Same problem with mine, and it over-stroked too. Since tolerances are tight on my frame, this meant the rockers hit the frame on full compression. Not good.

Not in my experience of the 2010 RP23 (heavily falling rate frame tends to show up bad bottom-out characteristics..!)

Not sure if above is related to an RP3/23 or Monarch but my RT3 has 2.5" exposed stanchion, as did the 4.2 it replaced, both pushed the o-ring off the end, both are supposed to be 200mm x 51mm shocks, the only difference is the RT3 lets the wheel move so far the tyre now hits my seat tube when I bottom the shock out, I can't remember the 4.2 doing this and I'm running the same tyres albeit with less tread.

I've increased the IFP pressure to 300psi (The IFP Valve comes with the Vivid Spanner if you're struggling to find one) would putting a couple of drop's of oil in there help at all or am I way off with this?

As I side note I doubt it would be under warranty since I filled the HV Sleeve with the foam rings RS sell so sending it back probably isn't an option - plus I do like tinkering!

Great thread here, very informative. So after reading all of this I decided to order the adaptor for the IFP pressure valve and get to tweaking. I am not a tech, but it all sounded so straight forward that I figured I would try it myself, but it appears I am having some technical issues now. When I screw the adaptor on to the pump and thread it to the IFP chamber it immediately starts to bleed air pressure. There is no way to not have the shock lose all its pressure so I cannot fill the chamber with air and now cannot use the shock. Has anyone experienced this?

Not sure if above is related to an RP3/23 or Monarch but my RT3 has 2.5" exposed stanchion, as did the 4.2 it replaced, both pushed the o-ring off the end, both are supposed to be 200mm x 51mm shocks, the only difference is the RT3 lets the wheel move so far the tyre now hits my seat tube when I bottom the shock out, I can't remember the 4.2 doing this and I'm running the same tyres albeit with less tread.

I've increased the IFP pressure to 300psi (The IFP Valve comes with the Vivid Spanner if you're struggling to find one) would putting a couple of drop's of oil in there help at all or am I way off with this?

As I side note I doubt it would be under warranty since I filled the HV Sleeve with the foam rings RS sell so sending it back probably isn't an option - plus I do like tinkering!

soundit is like it is either the wrong size (2.5"=64mm) or f'd up pretty good.

Great thread here, very informative. So after reading all of this I decided to order the adaptor for the IFP pressure valve and get to tweaking. I am not a tech, but it all sounded so straight forward that I figured I would try it myself, but it appears I am having some technical issues now. When I screw the adaptor on to the pump and thread it to the IFP chamber it immediately starts to bleed air pressure. There is no way to not have the shock lose all its pressure so I cannot fill the chamber with air and now cannot use the shock. Has anyone experienced this?

screw the adaptor onto the pump first, before connecting it to the shock.

My rt3 on a giant trance, tuned softer by a local tuner, with 200 lbs in the ifp chamber still won't get full travel unless pushed very hard on a cross country ride. It's harsh on compression even @ 35% sag. I gave up on it & had the stock float tuned by push, & the bike flows much better at the rear. I don't understand all the great praises for the monarch, perhaps for heavy weight riders on longer travel bikes?

i have to ask...
isn't a trance a 5" trail bike? if so, I would expect that it would have to be pushed VERY hard on a cross country ride to use up all 5" of travel.
I can figure on a 4' drop and a rough landing before I use up 5" of travel.

Well, I'm just under 150 lbs, & what most would consider age challenged, ha. I ain't a leaper.
I wanted the set up on my trance for the nearby cross country trails, some rock gardens & natural drops of maybe a foot or two. With the pushed float I still have a little rear travel to spare after most rides.
I think you should be able to set up almost any bike within preferred desired suspension parameters.
& I have a 6.7" travel reign for the knarley stuff.

As a response to los05, I remember that almost all the IFP psi is lost when the sdaptor/pump is installed, but when I pumped it back to desired pressure it held. (but some psi is probably lost on disconnect) Maybe your pump leaks or the adaptor isn't tight in the pump head? Also, there's supposed to be an o ring on the adaptor just above the threads.

screw the adaptor onto the pump first, before connecting it to the shock.

Originally Posted by kneecap

Well, I'm just under 150 lbs, & what most would consider age challenged, ha. I ain't a leaper.
I wanted the set up on my trance for the nearby cross country trails, some rock gardens & natural drops of maybe a foot or two. With the pushed float I still have a little rear travel to spare after most rides.
I think you should be able to set up almost any bike within preferred desired suspension parameters.
& I have a 6.7" travel reign for the knarley stuff.

As a response to los05, I remember that almost all the IFP psi is lost when the sdaptor/pump is installed, but when I pumped it back to desired pressure it held. (but some psi is probably lost on disconnect) Maybe your pump leaks or the adaptor isn't tight in the pump head? Also, there's supposed to be an o ring on the adaptor just above the threads.

Upon further inspection, my buddy noticed that the O-Ring was a little chewed up on the valve adapter. I swapped it with the one on the valve cover for testing purposes and was able to pump in air and make it stay, so problem solved there.

Now it brings me to my second issue. Now when I unscrew the adaptor from the shock, (pump attached) it bleeds a lot of air. I am filling the shock with about 220 PSI and when I remove it and put it back on to see how much was lost, the reading is at about 140psi. Which is an issue because I am not going to be able to get an acurate reading on the shock. Any ideas?

I have an RT3 on a Salsa Spearfish. I recently dropped the IFP to 210 and it seem to add a little plushness on the square edge stuff. I pulled the air can last night to lube the seals, and the can seals where completely dry.

The issue I had was when I added air back to the shock, I set the ifp at 190 and spring at 155. The shock would not compress and seemed to be locked. Finally, I ended up putting the IFP back at 210 and the shock worked as normal. I have no idea how the shim stack preload works on the RT3, but I don't see how the differential between IFP and spring pressure would have any affect on the action of the shock. What am I missing here?

@los05:
Cool, I was just about to suggest you check your O-ring for cuts. Glad that's working.

As for the disconnect. Assuming you've got a correctly made adapter (no reason to suspect that something's wrong), then the adapter comes off of the valve needle before the O-ring comes out of the port. That means the hiss you hear on disconnect is that small volume of air you got trapped between the needle and the O-ring which is at your ~220psi.

When you reconnect, you are now tapping the very small IFP chamber into your pump. Because the internal volume of your pump (basically the hose all the way to the gauge) is a significant fraction of the IFP chamber size, the pressure drops by the time it gets to the gauge.

Think of it this way: Let's say you have a gas tank in your car that holds 15 gallons and is completely full. You decide to install a 20 gallon gas tank and put all your gas in that tank. Your new tank now looks 3/4 full. Your total amount of gas isn't different, but your reference volume has changed.

The same goes for your shock situation. By measuring the system, you have changed the system. The fact that you still see 140psi when you reconnect tells me that it's probably fine. If you repeat what you've described a couple of times and always arrive at ~140psi, I'd say you're definitely fine.

BTW, you experience the same effect on the air can as well. But because the air can is a much larger volume compared to pump volume, you only see a few psi difference.

@ktm520: No idea, man. To my knowledge, there isn't any pressure sensitive valving in the RockShox line, but I don't own all of them nor have I opened all of them so I could be wrong. But that's the only way I can see what you're describing happening.

[QUOTE=HHMTB;8608164]@los05:
Cool, I was just about to suggest you check your O-ring for cuts. Glad that's working.

As for the disconnect. Assuming you've got a correctly made adapter (no reason to suspect that something's wrong), then the adapter comes off of the valve needle before the O-ring comes out of the port. That means the hiss you hear on disconnect is that small volume of air you got trapped between the needle and the O-ring which is at your ~220psi.

When you reconnect, you are now tapping the very small IFP chamber into your pump. Because the internal volume of your pump (basically the hose all the way to the gauge) is a significant fraction of the IFP chamber size, the pressure drops by the time it gets to the gauge.

Think of it this way: Let's say you have a gas tank in your car that holds 15 gallons and is completely full. You decide to install a 20 gallon gas tank and put all your gas in that tank. Your new tank now looks 3/4 full. Your total amount of gas isn't different, but your reference volume has changed.

The same goes for your shock situation. By measuring the system, you have changed the system. The fact that you still see 140psi when you reconnect tells me that it's probably fine. If you repeat what you've described a couple of times and always arrive at ~140psi, I'd say you're definitely fine.

BTW, you experience the same effect on the air can as well. But because the air can is a much larger volume compared to pump volume, you only see a few psi difference.

__________________________________________________
First of all, thanks for the reply...

Logically speaking that makes sense, and I can see how that can happen. However, if that in fact that is the case and if I am understanding your comment correctly, then that would mean that I could never get an accurate pressure reading after I initially disengage the valve correct? Therefore one would always have to depressurize the entire chamber if you wanted to modify/verify the pressure at a later time? For example, I fill it to ~220psi today, and then next week I decide I want to set it at 240psi. Could I just add 20lbs to the current reading of 130psi to make it 160psi or do I bring the reading all the way to 240psi which would technically be adding an additional 100psi?

BTW, I am always getting the same reading after I remove the pump and put it back on.

Please excuse my ignorance; I am just very new to all this tweaking and trying to understand this correctly so that I don't damage the shock by not having it setup properly.

@los05:
Don't feel compelled to apologize for ignorance. Without asking questions, how is one supposed to learn?

I'll try to be as not confusing as possible by starting from the top and posing this in a quiz format.

Let's say your IFP is complete discharged. I.E. If you press the needle, nothing comes in or out. The IFP is at atmospheric pressure. You attach your pump with adapter and pump to 220psi. You disconnect. What's in the IFP? Ans:220

You reattach the pump and adapter. Because the hose and gauge were at atmospheric (0 psi) before you attached, the air that was in the IFP must fill that space before it can give a reading on the gauge. Once it does this, your gauge says 140psi because when a given amount of gas expands to fill a larger volume the pressure drops (PV=nRT if you remember chemistry). If you disconnect the pump and adapter right now, what's in the IFP? Ans: 140

If instead of disconnecting when you see the 140 on the gauge, you instead pump back up to 220 and then disconnect, what's in the IFP? Ans: 220

What's the take away of this story? After you connect and everything stabilizes, what's on the gauge is what's in the IFP. The only way that's not true is if you have an adapter that doesn't physically depress the needle, but what you're describing does not indicate that to be the case.

So what does this mean from a verification standpoint? Well, you can't verify without having to pump back up. And verification is reliant on using the same pump/adapter every time and knowing what kind of pressure drop you would expect to see if the initial pressure were correct. In other words, pump up to 220, disconnect, reconnect, take reading, pump up to 220, repeat several times. The results should be repeatable. That's your expected pressure drop for that given IFP volume. If you ever adjust IFP volume, you'll need to redo this to find your new pressure drop expectation.

In reality, barring some stupid leak in your system (check that the valve is greased and seated right unlike mine was), you'll rarely need to verify the IFP setting once you have confidence in your pump/adapter/disconnect technique.

Ok, I kinda sorta promised TNC some pictures of the RP23 innards a while back so here they are. I know this is a Monarch thread, but this is where the conversation started.

First picture shows the bottom out O-ring that TNC and I were wondering about. Nothing particularly special. The shiny disc behind it is a flat washer/shim to prevent the O-ring from expanding over the stub that the shaft screws into when smashed on a full bottom out. The Marzocchi Roco air shocks I've seen don't have this shim so the O-ring can over-expand and then no longer work as a bottom out softener.

Second and third pictures show the piston assembly more or less in its assembled state. That cross shaped, ninja star thing above the piston is a ring that protects the shim stack from damage on top out.

Fourth picture is the the piston/shim stack/Pro-Pedal assembly exploded. I laid it out from the top row left to right and then bottom row left to right. I laid them out the same way except for the one part that is marked flipped because the detail would have been obscured. As it's too ambiguous to describe the orientation of how I removed a shim and put it on the table, you'll have to figure it out by looking at the actual piston relative to picture two.

The fifth picture shows Pro-pedal on/off pop off valve next to the shaft end nut that it seats on. It's this pop off valve you are moving when you switch the blue lever. The PP level knob governs the preload on the spring.

I was surprised when I took this thing fully apart for the pictures that there seems to be a two stage rebound setup. That's what the "flipped" part does. Everything else is as described in my previous message as far as I can tell.

Hope that helps someone. If not, it'll help me when I forget

So I took apart my Monarch 2.1 last night and my internals are very similar to what you have posted.(even though its a fox) My goal is to reshim it to my liking. I am having a hard time wrapping my head around what each shim stack actually does. I know that the two stacks on the main(blue) piston are compression(shaft side) and high speed rebound (under side). Those are obvious to me from tuning my forks. The smaller piston (under the main piston) and larger piston( on top) leave me scratching my head though. Im also confused on where the oil that passes through the rebound free bleed goes. Any insight would be appreciated.

The two smaller piston shim stacks are the comp and rebound check valves for the low speed circuits. The low speed compression circuit is from the preloaded poppet valve in the middle of the shock shaft, around the square edges of the piston bolt,, and out the check valve. Flow is controlled by the amount of preload on the poppet valve. The rebound circuit is through the hole in the shock shaft (below piston), around the square piston bolt, and out the check valve on top of the piston. Flow is controlled by a needle that closes the hole in the shock shaft.

The two smaller piston shim stacks are the comp and rebound check valves for the low speed circuits. The low speed compression circuit is from the preloaded poppet valve in the middle of the shock shaft, around the square edges of the piston bolt,, and out the check valve. Flow is controlled by the amount of preload on the poppet valve. The rebound circuit is through the hole in the shock shaft (below piston), around the square piston bolt, and out the check valve on top of the piston. Flow is controlled by a needle that closes the hole in the shock shaft.

That helps. What I was missing is that that bolt is square, allowing oil to pass on the sides of it and not just through the center. Thanks for the help.

@los05:
Don't feel compelled to apologize for ignorance. Without asking questions, how is one supposed to learn?

I'll try to be as not confusing as possible by starting from the top and posing this in a quiz format.

Let's say your IFP is complete discharged. I.E. If you press the needle, nothing comes in or out. The IFP is at atmospheric pressure. You attach your pump with adapter and pump to 220psi. You disconnect. What's in the IFP? Ans:220

You reattach the pump and adapter. Because the hose and gauge were at atmospheric (0 psi) before you attached, the air that was in the IFP must fill that space before it can give a reading on the gauge. Once it does this, your gauge says 140psi because when a given amount of gas expands to fill a larger volume the pressure drops (PV=nRT if you remember chemistry). If you disconnect the pump and adapter right now, what's in the IFP? Ans: 140

If instead of disconnecting when you see the 140 on the gauge, you instead pump back up to 220 and then disconnect, what's in the IFP? Ans: 220

What's the take away of this story? After you connect and everything stabilizes, what's on the gauge is what's in the IFP. The only way that's not true is if you have an adapter that doesn't physically depress the needle, but what you're describing does not indicate that to be the case.

So what does this mean from a verification standpoint? Well, you can't verify without having to pump back up. And verification is reliant on using the same pump/adapter every time and knowing what kind of pressure drop you would expect to see if the initial pressure were correct. In other words, pump up to 220, disconnect, reconnect, take reading, pump up to 220, repeat several times. The results should be repeatable. That's your expected pressure drop for that given IFP volume. If you ever adjust IFP volume, you'll need to redo this to find your new pressure drop expectation.

In reality, barring some stupid leak in your system (check that the valve is greased and seated right unlike mine was), you'll rarely need to verify the IFP setting once you have confidence in your pump/adapter/disconnect technique.

Yeap, makes perfect sense.. Thanks so much man, I've been racking my brain with this trying to figure out what the hell was going on with thing. Thanks for putting it in layman's terms as well... Greatly appreciated.

Could you posts some pics if you get a chance? I'm trying to wrap my head around why my shock hydraulically locked when I lowered the IFP.

I put it back together already, But have no had a chance to test it yet to see if I like the new shim stacks. There is a good change I will take it back apart to tinker with it again, and I post pictures. It looks exactly like the picture above though, Only a few minor differences.

No problem. I'd be curious to see what changes you made if you don't mind sharing. I've always wanted to play with re-shimming a fork/shock, but have never had the chance/time. I'm planning to tear into my RT3 this winter.

No problem. I'd be curious to see what changes you made if you don't mind sharing. I've always wanted to play with re-shimming a fork/shock, but have never had the chance/time. I'm planning to tear into my RT3 this winter.

The interesting thing is that when I took it apart, It was slippery (from the oil) and I dropped it. The shims and what came apart and I never got to see what the stock shim stacks consisted of(although I have a general idea). So I wrote down what my stacks are currently and will have to use that as my starting point. I have tuned many forks, but this is the first rear shock, So im excited to see what I can do with it.

Mullen, that sounds like something I'd do :-) Keep us updated. I've done a few shim shuffles on dirtbike forks, but no bike stuff. What characteristics of the shock are you looking to change?

I played with the ifp some more today and couldn't re-create the hydraulic lock it experienced the other night after lubing the air seals. So I dropped the ifp from 210 to 190, main at 155, and it got even more plush on the Spearfish, maybe a tad too much. I will probably run it like this for the 6hr race this weekend for the comfort factor. I typically like a firmer mid stroke.

My bike has a very low 2:1 leverage ratio and I find the "D" tune to be a little harsh over all and a little sluggish from being over damped. Im playing around with having a two stage stack for HSC. Im looking for it to open slightly on smaller hits to give better small bump sensitivity,. Then have the second stage be pretty stiff for good control on bigger hits. Im hoping to get a ride in here shortly if I can find the time.

On my first ride after messing with my IFP pressure, I snapped both chain stays in half. So I didn't get a whole lot of data that ride, and I've only had a couple of rides since putting the bike back together. I checked out of this thread after my breakage - thank you for the response.

I want to say that lowering my IFP from 250 psi to 200 psi (main can at 150 psi) has improved small bump compliance, which is what I am after, but I think I have changed too many variables to say right now. When I replaced my chain stays, I replaced all the bearings in the swing arm and rocker, so everything in the back end is new and clean and low friction. I can't decide if the bike feels so nice due to this or my shock tuning or both - more data needed. Ideally, I'd like to do some shuttles on the same trail, changing IFP between runs.

I do enjoy how easy it is to play with this component on the Monarch. On my old Fox Float, it took some experienced help and much more effort to get inside and change some things.

Originally Posted by HHMTB

Ok, I'll try to help. But please post anything new you learn so we all get better knowledge.

Completely deflate the main air can. If there's any significant pressure in there and you let out all the IFP pressure, you'll get a big bubble in the oil as air forces its way around the main shaft seal. If after letting all the air out of the main air can, the shock compresses a little due to negative air spring interactions, it'd probably be best to unscrew the air can off the shock completely.

Ok, so now you're ready to play with IFP. What you wrote, "So I remove the IFP access cap with the Schrader core removing tool. I fit the adapter to the end of my shock pump, and thread this whole unit into the IFP valve." is correct.

I usually dump all the existing IFP pressure first just to make sure that that valve is still functioning. In the case of my report, it wasn't so I had to pull it out and clean crap off the sealing face. After you're satisfied that it's all mechanically in order, start pumping.

As I mentioned in a post a short while back, set that IFP higher than your main can by some good amount. I used 30 or so psi greater, but you'll have to be the judge of your own comfort level. On a coil over, I'd say anything over 100 is good, but given an air shock, I'm staying above 170 psi on the IFP for this reason.

Yes, IFP pressure affects sag to a small degree. However it affects mid stroke and bottom out more as does actual IFP volume. I can't point you to a magic ratio as it varies from shock model to shock model due to dimensional differences. Also, you may like something entirely different from what I like.

Generally speaking, the higher the IFP pressure, the greater its effect on bottom out the more support you'll get mid stroke so you can lower the main air can pressure. It's a reasonable way to combat a wallowy shock up to a certain point. If you reach that limitation, you'll have to actually vary the IFP chamber volume. Less volume = more bottom out resistance/spring progressivity which can actually make the wallowing feeling worse in some cases.

Anyway, that's all I got time for now. Post your findings please and we'll talk some more.

ifp adapter?

Anyone know who has got these red adapters in stock? I have looked everywhere.

Just got a Monarch RT3 for my 2009 Racer X and am not impressed so far. Can't get it to use its full travel and even at 30 percent sag the small bump compliance is pretty harsh. Got the shock directly from Titus and they assure me it is the right tune for the bike (MM).

I am going to ride it a bit more to let it break in then try to mess with the ifp chamber. If that does not work, off to Push it goes.

Anyone know who has got these red adapters in stock? I have looked everywhere.

Just got a Monarch RT3 for my 2009 Racer X and am not impressed so far. Can't get it to use its full travel and even at 30 percent sag the small bump compliance is pretty harsh. Got the shock directly from Titus and they assure me it is the right tune for the bike (MM).

I am going to ride it a bit more to let it break in then try to mess with the ifp chamber. If that does not work, off to Push it goes.

Thanks.

Push currently doesnt tune Monarchs that are sent in. They only sell their version. Kinda silly but its the way it works for now. I hope the IFP tool works for you.